Manufacture of filaments and films from viscose.



CHARLES N. WAITE, OF LANSDOWNE, PENNSYLVANIA, ASSIGNOR, BY

MESNE ASSIGNMENTS, TO PENNSYLVANIA.

SILAS W. PETTIT, .OF PHILADELPHIA,

MANUFACTURE OF FILAMENTS AND FILMS FROM VISCOSE.

Specification of Letters Patent.

Patented March 27, 1906.

Application filed May 3,1904. Serial No. 206,173.

To all whom it may concern:

Be it known that 1, CHARLES N. WAITE, of Lansdowne, in the county of Delaware and State of Pennsylvania, have invented certain new and useful Improvements in the Manufacture of Filaments and Films from Viscose, whereof the following is a specification.

My invention is es ecially valuable in the manufacture of the aments commercially known as artificial silk, and I would refer to Letters Patent of the United States No. 622,087, dated March 28, 1889, and No. 716,778, dated December 23, 1902, as containing descriptions of typical and convenient methods of obtaining such filaments.

In processes of the character contem lated viscose (cellulose sulfo-carbonate) is forced through spinnerets into a bath capable of gelatinizing the viscose, whereby the filathus produced are set in the form ments iven to them by the spinnerets. Heretoore either an ammonium salt, such as ammonium chlorid or ammonium sulfid or sulfuric acid, has been em loyed as the efiicient agpnt of the setting-bat I have found that w en either ammonium salt aforesaid is used ammonium sulfid is liberated in large quantities and sulfur efiioresces on the filaments, imp airing their luster and rendering their color objectionable. I have also found that if sulfuric acid is used hydrogen sulfid is liberated, with the disadvantages'which are due to the resence of that poisonous gas, and sulfur is a so deposited in the filaments, making a second process necessary for its removal.

My invention is intended to avoid the objectionable features aforesaid, and to that end I roceed as follows: I employ for the setting so ution a bath consisting of acid sodium sulfite, (NaHSo Q into which the filaments or films are projected, with the result that the sodium hydrate inthe viscose is neutralized and the sulfur is converted into a material soluble in waterviz., sodium hyposulfite.

For the purpose of dehydrating the filaments and rendering them'firmer and less liable to abrasion during the subsequent finishing process than if treated solely with the settin -bath of acid sodium sulfite aforesaid find it advantageous to add a saline solution to said bath. For instance, I make a bath of saturated aqueous solution of acid sodium sulfite containing from eleven and one-half to twelve per cent. of available sulfurous acid and to this add ten per cent. of its weight of a saturated solution of ammonium sulfate or sodium chlorid.

It is to be understood that after the foregoing treatment the viscose films or filaments may be subjected to any desired finishing process.

Having thus claim- 1. The hereinbeforedescribed improvement in the manufacture of viscose products, which consists in initially subjectmg them to the action of a solution comprising an acid sulfite, substantially as set forth.

- 2. The hereinbeforedescribed improvedescribed my invention, I

.ment in the manufacture of viscose products, which consists in init ally subjecting them to the action of a solution comprising acid sodium sulfite, substantially as set forth.

3. The hereinbeforedescribed improvement in the manufacture of viscose products, which consists in initially subjecting them to the action of a solution comprising an acid sulfite and a dehydrating agent, substantially as set forth.

4. The hereinbeforedescribed improvement in the manufacture of viscose products, which consists in initially subjecting them to the action of a solution comprising acid sodium sulfite and a dehydrating agent, substantially as set forth.

5. The hereinbeforedescribed improvement in the manufacture of viscose products, which consists in initially subjecting them to the action of a solution comprising an acid sulfite and a saline dehydrating agent, substantially as set forth.

6. The hereinbeforedescribed improvement in the manufacture of viscose products, which consists in initially subjecting them to the action of a setting solution comprising acid sodium sulfite and ammonium sulfate, substantially as set forth.

In testimony whereof I have hereunto signed my name, at Philadelphia, Pennsylvania, this 2d day of May, 1904.

CHARLES N. WAITE.

'Witnesses:

ARTHUR E. PAIGE, ANNA F. GETZFREAD. 

